This invention relates to an inhalation device and specifically to an inhalation device that indicates both the level of the medicament and the number of doses dispensed over a predetermined period.
It is well known to treat patients with medicaments contained in an aerosol, for example, in bronchodilation therapy. The aerosol can be conveniently administered to a patient by means of an inhalation device comprising a tubular housing or sleeve for holding the aerosol container and an outlet tube leading out of the tubular housing. The aerosol dispensers used in such inhalation devices typically are sold in 100 and 200 dose sizes and have an outlet valve member at one end which can be opened either by depressing the valve member while the dispenser is held stationary or by depressing the dispenser while the valve member is held stationary.
In use, the aerosol dispenser is placed in the tubular housing with the outlet valve member of the dispenser communicating via a support with the outlet tube, for example, a nozzle or mouthpiece. When used for dispensing medicaments, for example in bronchodilation therapy, the housing is held by the patient in a more or less upright condition with the mouthpiece or nozzle of the inhalation device placed in the mouth of the patient. The aerosol container is pressed towards the support to dispense a dose of medicament from the container which is then inhaled by the patient.
Patient compliance with a doctor""s instructions on prescribed medication is extremely important in the treatment of medical disorders. Although the rate of compliance is higher when the patient must return to the hospital or physician""s office to receive the medication, most drug treatment regimens require the patient to administer the drugs at regular intervals without supervision by hospital personnel, the patient""s physician or other qualified medical personnel. Obviously, the treatment of a medical disorder will be frustrated if the patient does not administer the drugs as prescribed. In the past, physicians have had to rely on the patient""s self-interest in his or her own well being to assure that drugs are properly administered as scheduled.
With anti-anxiety or sedative/hypnotics, such as valium and barbiturates, it is widely recognized that there is a real possibility that the patient will abuse or become dependent on the drug. Past studies have suggested that physicians should avoid the prescription of barbiturates because of the risk of dependence and the high toxicity of the drugs.
Furthermore, many such drugs have a narrow therapeutic range and can have severe side effects. It is well recognized that controlling the dosing of these types of drugs is important in mitigating problems with side effects. Many drugs can be extremely expensive (e.g., certain purified peptides and proteins). Controlling patient dosing of these drugs can also have economic benefits.
Metered dose inhalers, nebulizers and dry powder inhalers have been used for many years to treat pulmonary disorders such as asthma A metered dose inhaler typically comprises a canister pressure-fitted with a metering valve, where the canister is filled with an aerosol formulation that includes a drug dissolved or dispersed in a propellant together with a surfactant. Nebulizers are devices which include mechanical or electronic devices (e.g., a piezoelectric element) to atomize a drug suspension positioned in a containment cup. Nebulizers include an air or other gas source to deliver the atomized drug to the patient as a fine mist. Dry powder inhalers include mechanical or electronic devices to produce a fine mist from a powdered drug composition.
Patient non-compliance while using inhalation devices has been recognized as a major medical problem. It is generally believed that most patients underdose themselves. Furthermore, over use has been observed in various studies on days following visits to the physician""s office.
Therefore, there is a need to improve patient compliance with prescribed dosing schedules. There is also a need for an inhalation device which can provide some assurance that a patient is not circumventing a dosing schedule by not inhaling the medicament.
A further disadvantage arising from use of currently available devices is that the patient cannot determine the amount of medicament in the aerosol container at any given time. In an extreme case this could mean that the patient, possibly suffering from severe bronchospasm and needing a dose of medicament, will find that the aerosol container will not dispense a dose because its contents have already been exhausted. There is a need for an inhalation device that avoids this problem.
The present invention relates to an inhalation device, that is either disposable or reusable. Specifically, the present invention provides an inhalation device that, when used with a medicament dispenser in any available dose size, indicates both the level of the medicament and the number of doses dispensed for a predetermined time period. In this manner, the present invention provides for easy and accurate dosage monitoring of the medicament, either as a single dose or multiple doses.
Examples of use of the inhalation device include delivery of a medicament to a patient""s mouth, nostril, ear canal, or eye. The inhalation device can be used to dispense such drugs as beta-agonists such as albuterol (salbutamol), isoproterenol, ephedrine, epinephrine, salmeterol and terbutaline; corticosteroids such as triamcinolone acetonide, beclomethasone diproprionate, dexamethasone and aldosterone; allergic mediators such as cromcyln sodium; antibiotics; and anticholinergics. Moreover, these drugs can be dispensed by the inhalation device whether dissolved or dispersed in a propellant together with a surfactant or in a dry powder.
The inhalation device includes a generally tubular housing defining a lumen, a level indicator device and a dose indicator device. The housing terminates in a nozzle which defines a dispensing lumen terminating in a dispensing nozzle opening and further includes a replaceable cap.
The level indicator device is operably associated with the housing to indicate a remaining amount of the medicament in a liner fashion, while the dose indicator device is operably associated with the level indicator device and indicates the number of doses dispensed. In one particular embodiment, the level indicator and dose indictor devices include an advance ring operably associated with an advance tube. The advance tube has a helically wound groove operably associated with a level display device, and includes an indicia device operably associated with a display port to indicate the number of doses dispensed. Furthermore, the dose indicator device can be reset to zero so that the number of doses taken in any predetermined time period can be monitored.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description and from the accompanying drawings.